This program consists of basic and applied components. The basic studies will be directed at: 1) exploring the mechanism by which cell dehydration and cell volume reduction resulting from the freezing out of extracellular water results in cell membrane damage. 2) examining the kinetics of water and glycerol diffusion into and out of various cell types maintained in tissue culture. 3) exploring the effects of dimethylsulfoxide or other agents on the permeability of the cell to water and glycerol. The applied studies will be directed at the preservation of rabbit and dog kidneys by freezing. Experiments will initially be limited to perfusion with glycerol followed by slow freezing to temperatures ranging from -20 degrees to -40 degrees for periods of the order of one to two weeks in duration. Should this approach prove to be unsuccessful, kinetic freezing protocols will be explored using gas perfusion prior to freezing, two-step cooling, storage in liquid nitrogen vapor and thawing by microwave heating. The use of low molecular weight dextran, aspirin and heparin will be explored as means of preventing platelet thrombogenesis following re-implantation.